Process for breaking petroleum emulsions



Patented Jan. 27, v 1953 UNITED STATES PATENT OFFICE PROCESS FOR BREAKING PETROLEUM EMULSIONS Melvin De Groote, University City, Mo., assignor to Pctrolite Corporation, a corporation of Delaware No Drawing. Application December 14, 1950, Serial No. 200,863

9 Claims. 1

emulsions which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsification under the conditions just mentioned, are of significant value in removing impurities particularly inorganic salts from pipe- .line oil.

. Demulsification as contemplated in the present application includes the preventive step of commingling the demulsifier with the aqueous component which would or might subsequently become either phase of the emulsion, in absence of such precautionary measure. Similarly, such demulsifier may be mixed with the hydrocarbon component.

.The demulsifying agent employed in the present process is a fractional ester obtained from a polycarboxy acid and a diol obtained by the oxypropylation of a dihydroxy ether of glycerol. This glycerol ether is obtained by reacting-one mole of propylene glycol ethyl ether with one mole of 'glycide or any comparable procedure which produces the same compound or equivalent isomer thereof. Propylene glycol ethyl ether can be prepared in any suitable manner and also can be purchased. My preference is to treat the glycerol ether of propylene glycol ethyl ether with sufficient propylene oxide so the resulting product is w-aterinso1uble. It is to noted that the original glycol itself, i. e., propylene glycol ethyl ether, and also the dihydroxy compound obtained by reaction with glycerol monochlorohydrin or glycide, is water-soluble. Similarly, the compounds are kerosene-insoluble. It is my preferenceto react such dihydroxy ether notonly with sufiicient propylene oxide to bring it Within the lower molecular weight range subsequently pointed out, but more specifically with enough propylene oxide to render the compound water insoluble and preferably either dispersible or soluble in kerosene.

. 2 The monohydrlc alcohol is obviously of the following structure:

CzHsOCsI-IsOI-I The glycide derivative is of the followin structure:

OzH O CsHuO CaHs It is this latter compound which is subjected to oxypropylaticn. If for convenience this latter compound is indicated thus: I-IOR'OH, the product obtained by 'oxypropylation may be indicated thus:

with the proviso that n and 11. represent whole numbers which added together equal a sum varying from 15 to 80, and the acidic ester obtained by reaction of the polycarboxy acid may be indicated thus in which the characters have their previous significance, and n" is a whole number not over 2 and R is the radical of the polycarboxy radical and preferably free from any radicals having more than 8 uninterrupted carbon atoms in a single group, and with the further proviso that the parent diol prior to esterification be preferably water-insoluble and kerosene-soluble.

Attention is directed to the co-pending application of C. M. Blair, Jr., Serial No. 70,811, filed January 13, 1949, now Patent 2,562,878, granted August '7, 1951, in which there is described, among other things, a process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of an esterification product of a dicarboxylic acid and a polyalkylene glycol in which the ratio of equivalents of polybasic acid to equivalents of polyalkylene glycol is in the range of 0.5 to 2.0, in which the alkylene group has from 2 to 3 carbon atoms, and in which the molecular weight of the product is between 1,500 to 4,000.

Similarly, there have been used esters of dicarboxy acids and polypropylene glycols in which -2 moles of the dicarboxy acid ester have been reacted with one mole of a polypropylene glycol having a molecular weight, for example, of 2,000 so as to form an acidic fractional ester. Subsequent examination of What is said herein in comof the diol by reacting propylene glycol ethyl ether with glycide or its equivalent;

Part 2 will be concerned with the oxypropy'lation of the diol obtained in the manner previously described in Part 1;

Part 3 will be concerned with the preparation of esters'from the aforementioned.oxypropylation derivatives;

Part 4 will be concerned with the structure of the herein described diols and their significance "in light of what is said subsequently;

Part 5 will be concerned with the use of the products herein described as demulsifiers for breaking water-inoil emulsions; .and

Part 6 will be concerned with certain derivatives which can be obtained from the diols of the type aforementioned.

As pointed out previously the :monohydric compound CzHsOCzI-IcQI-I can beprepared in the customary manner or p111- chased in the open market. Such compound is .then reacted with .a suitable reactant .such as glycide so as to give a dihydroxy compound. The reaction maybe shown thus:

021150 CaHaOH CH2OHCHCH .CzHsO CaHnO Q3115 LOH In examining the above reaction it is obvious that an isomeric mixture could be obtained for a number of reasons. In the first place propylene glycol is unsymmetrical in the sense that there is present one primary and one secondary alcohol-radical. For the present purpose itis immaterial to which oxygen atom the ethyl group "is I attached. Stated another way, one could :start with ethyl alcohol and react with propylene oxide mole for'mole using different catalystsso that in one instance the epoxy ring would open to give a terminal primary alcohol and in the other instance -would open to give a terminal secondary alcohol. Either isomer could then be reacted or beta glycerol monochlorohydrin. Attention is directed again to the fact that in the previous formula and in the formulas in the claims it would be immaterial whether the free hydroxyl radicals prior to esterification are present as attached to the first and third terminal carbon atoms, or second "and third carbon atoms. This is simply an isomeric difference dependingv on how the epoxy ring is ruptured in the case of glycide,

or whether one employs glycerol alpha monochlorohydrin or glycerol beta monochlorohydrin. Other suitable procedure involves the use of epichlorohydrin in a conventional manner. For instance, the oxypropylated compound can be treated with epichlcrohydrin and the resultant product treated with caustic soda so as to reform the epoxy ring. The epoxide so obtained can then be treated with water so as to yield a compound having two hydroxyl radicals attached to two of the three terminally adjacent carbon atoms.

Attention is directed to "the fact that the use of-glycide'requires extreme caution. "This is particularly true on any scale other than small laboratory or semi-pilot plant operations. Purely from the standpoint of safety in the handling of glycide, attention is directed to the following: (a) If prepared from glycerol monochlorohydrin. this product should be comparatively pure; (b) the-glycide itself should be as pure as possible as the efiect of impurities is diilicult to evaluate; (c) the g'lycide should be introduced carefully and precaution should be taken that it reacts as promptly as introduced, "1. e., that no excess of g'lyc'ide is allowed to accumulate; id) zall necessary precaution's'hould'be taken that glycide cannot polymerize'per 'se; (c) due to 'the'high boiling point of glyc'ide-one can readily employ atypical separatable glass resin pot as described'inU. S. Patent No. 2,499,370, dated March 7, 1950, to De Groote and Keiser, and ofiered for sale by numerous laboratory supply houses. If such. arrangement is used to prepare laboratory-scale duplications, then care should be taken that, the heating mantle can be removed rapidly :so as to allow-for cooling; or better still, through an added opening at the top, the glass resin pot or comparable vessel'should'be equipped'withza stainless steel cooling coil so that the pot can "be cooled more rapidly than by mere removal of mantle. If a stainless steel coilis introduced it means that the conventional stirrer of the paddle type *is changed into the centrifugal type which causes the fluid or'reactants to mix due to'swirling action in the center of the pot. Still better is the use of a laboratory autoclave; butfin any event when the initialamount of glycide'is'added to a suitable reactant, the speed of reaction should be conwith g'lyc'ide and again theepoxy ring could open,

trolled by the-usual factors, such as .(a) the :addition of glycide; (b) the elimination of external heat; and (c) "the use of cooling coil so there .is no undue rise in temperature. All the foregoing is merely conventional but is included due to the hazard in handling glycide.

Example l The equipment used was a glass resin,- of the kind described above. Into this resin pot were charged :5 gram moles of propylene glycol ethyl ether. This represented 520 grams. To thiszthere was added approximately 1% of-sodium methylate equivalent to 5.25 grams. The temperature of the reaction mass was raised to about 0. 5 1110185 of slycide, equivalent to 3'70 grams, were added slowly overa period'of'fihours at therate of about 60 grams per hour, or a gram per minute. Whenever the temperature tended to rise past 130 C. the reaction mass was cooled; if the temperature showed a tendency to drop below 114 to 117 C. the reaction mass was heated. When all the glycide had been added the reaction mass was stirred for approximately one hour longer at 135 C., and then was heated to a temperature below the decomposition point of glycide, for instance, 140 C'., and held at this temperature for another hour. In this particular reaction there is less hazard than is usually the case insofar that the amount of glycide added was comparatively small and it was added slowly. Even so, such oxyalkylation could be conducted with extreme care. Other catalysts can be em-' ployed such as caustic soda, or caustic potash, but purely as a matter of convenience I have employed sodium methylate. The amount of catalyst can be increased but the objection is that more alkaline material must be subsequently removed prior to esterification as described in Part 3, following, or the reaction may tak place too rapidly or one might possibly polymerize the glycide itself rather than have it react with the glycol ether.

PART 2 For a number of well known reasons equipment, whether laboratory size, semi-pilot plant size, pilot plant size, or large scale size, is not as a rule designed for a particular alkylene oxide. Invariably and inevitably, however, or particularly in features; (a) a solenoid controlled valve which shuts 011 the propylen oxide in event that the temperature gets outside a predetermined and 'Otherwise, the equipment is substantially the the case of laboratory equipment and pilot plant size the design is such as to use any of the customarily available alkylene oxides, i. e., ethylene oxide, propylene oxide, butylene oxide, glycide epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for oxyethylation as about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly above, as for example 95 to 120 C. Under such circumstances the pressure will be less than 30 pounds per square inch unless some special procedur is employed as ;is sometimes the case, to wit, keeping an atmosphere of inert gas such as nitrogen in the vessel during the reaction. Such low-temperature-low reaction rate oxypropylations have been described very completely in. U.' S. Patent No.- 2,448,664, to H. R. Fife et al., dated September'l;

1948. Low temperature, low pressure oxypropylations are particularly desirable wher the.

compound being subjected to oxypropylation contains one, two or three points of reaction only, such as monohydric alcohols, glycols and triols. Since low pressure-low temperature-low ,,re-.

action speed oxypropylations require considerable time, for instance, 1 to '7 days of 24 hours each to complete the reaction they are conducted as a rule whether on a laboratory scale, pilot plant scale, or large scale, so as to operate automatically. The prior figure of seven days applies especially to large-scale operations. I have used conventional equipment with two added automatic same as is commonly employed for this purpose where the pressure of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit continuous oxyalkylation whether it be oxypropylation or oxyethylation.

,With certain obvious changes the equipment can be used also to permit oxyalkylation involving the-use of glycide where no pressure is involved except the vapor pressure of a solvent, if any, which may have been used as a diluent. I

As previously pointed out the method of using propylene oxide is the same as ethylene oxide. This point is emphasized only for the reason that the apparatus is so designed and constructed as to use either oxide.

' The oxypropylation procedure employed in the preparation of the oxyalkylated derivatives has been uniformly the same, particularly in light of the fact that a continuous automaticallycontrolled procedure was employed. In this procedure the autoclave was a conventional autoclave made of stainless steel and having a capacity of approximately 15 gallons and a working pressure of one thousand pounds gauge pressure. This pressure obviously is far beyond any requirement as far as propylene oxide goes unless there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as the variable-speed stirrer operating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge. manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, such as propylene oxide or ethylene oxide, to the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave, such as a cooling jacket, and, preferably, coils in addition thereto, with the .jacket so arranged that it is suitable for heating with steam or cooling with water and further equipped with electrical heating devices. Such autoclaves are, of course, in essence smallscale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations an autoclave having a smaller capacity, for instance, approximately 3% liters in one case and about 1% gallons in another case, was used.

Gontinuous operation, or substantially con container consists essentially of a laboratorybomb having a'capacity of about one-half gallon, or somewhat in excess thereof. In some instances a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb 7 was equipped, also, with an inlet for charging,

and an eductor tube going to the bottom of the assume container: s as to p rm dis hsreina o ethylene. s iquid; pha e. to the, au ave! A omb h a c ci y f ab t po nds was. used in connection-with the 15-.gallon autoclave. Other conventional equipment consists, of; course. of tnerupt re disc, pr s ure ga e. igh feed g a hermo erconnec i n. fo n t o gen; for pressuring, bomb. etc. The bomb was pla on a: scale d r us e o e t on between he b m a d t e utoclave were fl xible stain e s Steel ose; or tubing sothat continuous weighings could be made without. breaking or making any connections. This applies also to the ni rog n n which. was. d. t p essure h bomb reservoir. To the extent that itw'asrequir any other usual. conven ional. pr edure, or d i i n whi h pro i d r a erafety was used, of course, such as safety glass protective s reens, t

A nt D i ir c d ga n. t w at. ha e n said. pr viou lyn gard. to a o atico t o wh chv shu off he p opyl ne o i e n ve om-- per-ature of reactionpasses out of the predeter-a mined range; or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all, oxypropylations become uniform in; that the: reaction temperature was held within a few degrees of any selected point, for instance, if 105 C. was selected as theoperating temperaturethe maximum point would be at the most; 110 Q. or 112 C., and thelower point would be. 95," or possibly 98 0. Similarly, the pressure; w s held a pproxima ly 3 po nds w t in e 5 pound variation one way or the other, but. might: drop to practically zero, especially where no, solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylaq tions at 200 Numerous reactions were con: ducted in which the time varied from one day- (24 hours) p to three days (72 hours), for completion of the final member of a series. In some instances the. reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation is concerned.

The minimum time recorded was about a, 1%; .19 11. period. Reactions indicated, asbeing CQm-r. plete in two hours or thereabouts may have been complete in a lesser period of tim fin lightqf he. o a c q pm n em o ed. This. en:-

plies also to where larger autoclaves are usedand;

the reactions were complete in approximately- 6 or 8 hours- In, th ad i n. o p op en o ide. in e a to ave. qu pm n s r as: os ble. the valves were set so all the propylene. oxide was fed in at a rate so the predetermined amountreacted inv the fi s wo-th rds oi he elec e peri r in nce, if th e ec d per o was three hours the rate was set so the oxide could be fed in in two'hoursor less. This meant that if; the reaction was interrupted automatically for a period of time for the pressure to drop, or the temperature to drop, the predetermined amount of oxide would still be added in most instances well within the predetermined time period. In one experiment the addition of oxide was made over a comparatively long period, i. e., 10 hours. In such instances, of course, the reaction could be speeded up to quite a marked degree.

When operating at a comparatively high temperature, ior instance, between 150,to 200 C. an u a d. a kyl n x de such asu pylons ide. m ke i pres e f l n he. increasente s ue or he Qonsistencr at. a hi her r ssure, ilowev n at. a. ow eno gh, em e ur i may happen that the propylene oxide goes in as a; qu dand if it r m ns nre ct d t e e. s. o c r a nhe nt da er and. ap ro r at stc s mus be a en. o afeg d. a a n t. h s possibility; if need be a sample must be withdrawn and examined for unreacted propylene oxide, One obvious procedure, of course, is to oxypropylate at amodestly higher temperature, for instance, at 140? to 150 C. Unreacted oxide afie s' et rm na qn of he, a e v o hy rqx value, of the hydroxylated compound obtained. fi he he. ol ula Weight 01-; he c mpqund; oward he l t er. g s j c con th on r et me r u r d a ven amount. o x e sib e ana ion i ha e molecule. n la th o tun ty for random reaction is decreased. Inversely,

the lower the molecular weight th faster the reaction takes place. For this reason, sometimes at least, increasingthe concentration of the cata lyst; does not appreciably speed up the reaction,

particularly when the product subjected to oxyalkylation has a comparatively high molecular weight. However, as has been'pointedout previously, operating at, a low pressure and a low temperature even in large scale operations as much as a week or ten days time may elapse to obtain some of the higher molecular weight derivatives from monohydric or dihydric"mate rials.

In a number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined amount of propylene oxide had passed into the reaction the scale movement through a time operatingdevice was set foreither one to two hours so that reaction continued for 1 /2' to 2 hours after the final. addition of' the last propylene oxide and thereafter the operation was shut down. This particular device is particularly suitable for use on larger equipment than laboratory size autoclaves, to wit, on semi-pilot plant or pilot plant size, as well'as on large scale size. This final stirringperiod is-intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range was controlled automatically by eitheruse of cooling water, steam, or electrical heat, so as to raise or lower the temperature. The pressuring of' the propylene oxide into the reaction vessel was also automatic insofar that the feed stream was set for a slow continuous run which was shut on in case the pressure passed a predetermined point as previously set out. All the points of" design, construction, etc., were conventional including the gauges, checl; valves and en: tire equipment. As faras I am aware at least two firms, and possibly three; specialize in autoclave equipment such as I have employed in the laboratory, and are prepared to furnish equipment of this same kind, Similarly pilot plant equipment is available. This point is simply made as'a precaution in the direction of safety. Oxyalkylations, particularly involving ethylene oxide, glycide, propylene oxide, etc., should not be conducted except in equipment specifically designed for the purpose.

Example 11) The dihydroxy compound employed was the one previously described and which, for purpose of QHYBQIQIL Q l scri e 5, ro other oi pr p len gl o ethyl th r h ausclave employed was a small autoclave having a capacity of approximately one gallon. This autoclave was equipped with various automatic devices. In some instances the oxypropylations were run with automatic controls and in other instances, since the oxypropylation was very short, with manual control. Needless to say, it was immaterial which way the autoclave was handled.

172 grams of the dihydroxylated compound previously described were charged into the autoclavealong with grams of caustic soda. It is to be noted that the sodium methylate used in the glycide reaction was permitted to remain in the reaction mass. This meant that the concentration of catalyst was slightly higher than indi- 15 cated by the amount of caustic added. The reaction pot was flushed out with nitrogen. The autoclave was sealed and the automatic devices adjusted for injecting '77 8 grams of propylene oxide in a period just short of 3 hours. sure regulator was set for a maximum of 35 pounds per square inch. This meant that the bulk of the reaction could take place and probably did take place at a comparatively lower pressure. This comparatively lower pressure was the result of the fact that at least in part considerable catalyst was present. The propylene oxide was added at approximately 300 grams per The pres- 20 propylene oxide. This was introduced without any additional catalyst. The conditions of reaction as far as temperature and pressure were concerned were substantially the same as in Example 1 b, preceding. The time required to add the oxide was a little less than in either one of the two preceding examples, being 1% hours. At the completion of the reaction part of the reaction mass was withdrawn and the remainder subjected to the final oxypropylation step as described in Example 41) immediately following.

Example 4b 323 grams of the reaction mass identified as Example 32), preceding, were subjected to further oxypropylation with 130 grams of propylene oxide. This was reacted without the use of any more catalyst. The conditions of reaction as far as temperature and pressure were concerned were substantially the same as in Example 1b, preceding. The time required to add this oxide was about the same as in the average of the preceding examples, i. e., two hours.

What has been said herein is presented in tabular form in Table '1 immediately following, with some added information as to molecular weight and as to solubility of the reaction product in water, xylene and kerosene.

TABLE 1 Composition Before Composition at End M W Ex. i by I M E Time, No. no. Oxide om- Theo. 11.0. Oxide Cata- 5 2 6 lbs. Hrs.

Amt, Amt., lyst, Mo]. Amt., Amt, lyst, sq. in.

lbs. lbs. lbs. Wt. lbs. lbs. lbs.

lb- 172 15 980 172 778 15 896 110 2}i 2b.. B4. 6 384 7. 4 1, 988 84. 6 860 7. 4 1, 355 110 35 2 3b" 46. 3 469. 6 4. 1 2, 998 46. 3 729. 6 4. 1 1, 440 110 35 1% 4[J 19. 2 302. 1 1. 7 4, 178 19. 2 432. 1 1. 7 1, 730 110 35 l The hydroxylated compound is the glycerol ether of propylene glycol ethyl ether.

hour in this instance. The time required to add allthe oxide was about 2 /2 hours. More important, the selected temperature range was 110C.

(just moderately above the boiling point of water). The initial introduction of propylene oxide was not started until the heating devices had raised the temperature to about 105 C. At the completion of the reaction the molecular weight, based on a hydroxyl determination, was

immediately following.

Example 2b 4'75 grams of the reaction mixture identified as Example 1b, preceding, were reacted with an additional 476 grams of propylene oxide without adding any more catalyst. The conditions of reaction as far as temperature and pressure were concerned were substantially the same as in Ex ample 1b, preceding. The time required to add the oxide was a little less than in the case of Example 1b, being only about 2 hours in the present instance. At the completion of this stage oi oxypropylation part of the sample was withdrawn and the remainder subjected to further oxypropylation as described in Example 3b, immediately following.

Example 311 Example 1b was emulsifiable in water, soluble in xylene and insoluble in kerosene; Example 2b was insoluble in water, soluble in xylene, and dispersible in kerosene; Examples 3!) and 4b were both insoluble in water, but soluble in both xylene and kerosene.

Thefinal product, i. e., at the end of the oxypropylation step, was a somewhat viscous ambercolored fluid which was water-insoluble. This is characteristic of all various end products obtained in this series. These products were, of course, slightly alkaline due to the residual caustic soda employed. This would also be the case if sodium methylate were used as a catalyst.

Speaking of insolubility in water or solubility in kerosene such solubility test can be made simply by shaking small amounts of the materials in a test tube with water, forinstance, using 1% to 5% approximately based on the amount of water present.

Needless to say. there is no complete conversion of propylene oxide into the desired hydroxylated compounds. This is indicated by the fact that the theoretical molecular weight based on a statistical average is greater than the molecular weight calculated by usual methods on basis of acetyl or hydroxyl value. Actually, there is no completely satisfactory method for determining molecular weights of these types of compounds with a high degree of accuracy when the molecular weights exceed 2,000. In some instances the acetyl value or hydroxyl value serves as satisfactorily as an index to the molecular weight as any 7 other procedure, subject. to the above limitations,

11 and especially in the higher molecular weight range. If any difficulty is encountered in "the manufacture of the esters as described in Part 3 the stoichiometrical 'amount of acid oracid compound should-be taken which corresponds to the indicated acetyl or hydrox-yl value. This matter has been discussed in the literature and is a matter of common knowledge and requires'no-further elaboration. In 'fact, it is illustrated by some of the examples appearing inthe patent previously mentioned.

PART 3 As previously pointed out the present invention is concerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately preceding, and polycarboxy acids, particularly dicar-boxy acids such as adipic acid, phthalic acid, or anhydride, succinic acid, diglycollie acid, .sebacic acid, azelaic acid, acon-itic acid, maleic acid or anhydride, citraconic acid or anhydride, maleic acid or anhydride adducts as obtained by the 'Diels-Alder reaction from products such as maleic anhydride, and cyclopentadiene. Such acids should be beat stable so the'yare not decomposed during esterification. They .may contain as many as 36 carbon atoms as, "for example, the acids obtained by dimerization of unsaturated fatty acids, unsaturated monocarboxy fatty acids, or unsaturated monocarbdxy'acid's having 18 carbon atoms. Reference to the acid in the hereto appended claims obviously includes the-anhydrides or any other obvio'us equivalents. My preference, however, 'is, to use polycarboxy acids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) from polyearboxy acids "and glycolsor other hydroxylated compounds is wellknown. Needless to'say, various compounds may be used such 'as'the'low molal esterfthe'anhydrida the i'acyl chloride, etc. However, for :purposeof economy :it'is customary to use .either the acid or the anhydride. A conventional .procedure i s employed. .On a laboratory scale onecanemploy a resin-pot of the kind described-in U.:S.-Pa'tent No. 2,499,370, dated March 7, 1950 to DeGroo-te 8: Keiser, and .particularly with one more -opening to permit "the use of a porous spreader i if hydrochloric acid-gas isto be used asa catalyst. Such device er absorption spreader consists of minute alundum thinrbles whichare-eonnectedt'o a glass tube. "One can'a'dd asulfonic"acid'such'aspara teluen'e suuo'mc 'acidas'acatalyst. There i's' some objection to thislbe'causein some instancesthele is "some evidence that this acid catalyst tends to decompose or "rearran e the ox r'opylate'd compounds, "and partic'ularly likely to do i f the esterific'ation temperature is too "high. .'In the case ofpolycarboxy acids such as diglyc ollic acid, which is strongly acidic th ere is no need to add any catalyst. The use 'of hydrochloric .gashas one advantage over .paratoluene sulfonic acid and that is that at the end ort ie reaction it can be removed by fiushing out withnitrogen, whereas there is no reasonably convenient means available'of removing the paratoluene 'sulfonic acid or-other sulfonic acid employed. If hydrochloric acid is employed one need only pass the gas through at'an-exceedingly slow-rate so as to keep the reaction -mass acidic. Only a trace of acid need be 111136891113. I have employed hydrochloric acid :gas or the aqueous acid itself to eliminate the initial basic material. My -preie'rence, how- 1 2 ever, is to use no catalyst whatsoever andto in sure complete dryness of the'diol'as described in the final procedure just preceding Table 2.

The products obtained in Part 2 preceding may contain'a basic catalyst. As a general procedure I have added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowed to stand overnight. It is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the produ'ct'i's substantially free from water the distillation steps. This preliminary step can be carried out in the flask to be usedfor esterification. If there is any further deposition of sodium chloride during the reflux stage needless to say a second filtration may be required. In any event the neutral or slightly acidic solution of the oxypropylated derivatives described in Part 2 is then diluted further with sufiicient xylene decalin, petroleum solvent, or the like, so that one has obtained approximately a 45% solution. To this solution there is added a polycarboxylated reactant as previously described, such as phthalic anhydride, succinic acid or anhydride, diglycollic acid, etc. The mixture is refiuxed until esterification is complete as indicated .by elimination of water or drop in canboxyl value. Needless'to say, if one produces a half-ester from an anhydride such as phthalic anhydride, no water is eliminated. However, if it is obtained from diglycollic acid, for example, Water is eliminated. All such procedures are conventional and have been so thoroughly described in the literature that further consideration will be iinbiited to a few examples and a comprehensive Qther procedures for eliminating the basic residual catalyst, if any, can be employed. For example, the oxyalkylation can be conducted in absence of a solvent or the solvent removed after oxypropylation. Such oxypropylation end product can then'be acidified with just enough concentrated hydrochloric acid tojust neutralize the residual basic catalyst. To this .productone can then add a small amount of anhydrous sodium sulfate (sufficient in quantity to take up any water that is present) and then subject the mass to centrifugal forceso as ,to'eliminate the sodium ulfate andprobably the sodium chloride formed. The clearsomewhat viscous straw-colored amber liquid so obtained may-contains small amount of sodium sulfate or sodium chloridebu't, in any event, is perfectly acceptablefor esterification in the manner described.

It is to be pointedout that the products here described are not polyesters the sense that there is a pluralityof both diol radicals and acid radicals; the product is characterized by having only one diolradical.

In some instances and, in fact, in many instances I have found that in spite of 'the dehydration methods employed abov'e'that a mere trace of water still comes through'and that this more trace of water certainly interferes with the acetyl or hydroxyl value determination, at least when a number'of conventional procedures are used and may retard'esterification, particularlywhere there is no sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I havep'referred to use the following procedure I-have employed about 200 grams of the diol as described inePart :1, preceding; 1 have added about 60 grams of benzene, and then refluxed this mixture in the glass resin pot using a phaseseparating trap until the benzene carried out all the water present as water of solution or the equivalent. Ordinarily this refluxing temperature is apt to be in the neighborhood'of 130 to possibly 150 C. When all this water or moisture has been removed I also withdraw approximately 20 grams or a little less benzene and then add the required amount of the carboxy reactant and also about 150 grams of a high boiling aromatic petroleum solvent. These solvents are sold by various oil refineries and, as far as solvent effect act as if they were almost completely aromatic in character. Typical distillation data in the particular type I have employed and found very satisfactory is the following:

After this material is added, refluxing is con- 30 14 tillation, and particularly vacuum distillation, then the high boiling aromatic petroleum solvent might well be replaced by some more expensive solvent, such as decalin or an alkylated decalin which has a rather definite or close range boiling point. The removal of the solvent, of course, is purely a conventional procedure and requires no elaboration.

In the appended table Solvent #7-3, which appears in numerous instances, is a mixture of '7 volumes of the aromatic petroleum solvent previously described and 3 volumes of benzene. Reference to Solvent #7 means the particular petroleum solvent previously described in detail. This was used, or a similar mixture, in the inanner previously described. A large number of the examples indicated were repeated employing decalin, using this mixture and particularly with the preliminary step of removing all the water. If one does not intend to remove the solvent my preference isv to use the petroleum solvent- ,benzene mixture although obviously any of the other mixtures, such as decalin and xylene, can be employed.

The data included in the subsequent tables, i. e., Tables 2 and 3, are self-explanatory, and very complete and it is believed no further elaboration is necessary:

TABLE 2 111115.05 Ex. Ex Theo. iff: x c tual wa Pcly-. No. of No. of M. W. yase I b Acid Hyd. of gffi g droxyl on Polyearboxy Reactdnt 2 2? Ester Cmpd H. O. H C Value Aging] (grs) ant (grs.)

980 115 Y 125 895 GM 1,925 55.5 52.9 1, 355 55 2, 998 34.1 71.0 1, 410 318 45 1, 17s 27. 9 55. 0 1, 730 1 15 950 115 125 395 we 25 1, 923 55. 5 s2. 9 1, 355 59, 0 2, 293 31. 1 71. 0 1, 440 0 4, 17s 27. 9 55. 0 1, 720 0 15 930 115 125 895 350 2b 1, 988 56. 5 82. 9 l, 356 3g 0 2, 993 31.1 71.0 1, 40 3M 45 4,173 27.9 55. 0 1, 730 15 930 895 4M 25 1, 92s 55. 5 s2. 9 1, 555 0 25 2, 998 34.1 71. 0 1, 440 45 0 45 4, 17s 27. 9 55. 0 1, 730 45,0 15 950 115 125 295 450 25 1, 055 55.5 32.0, 1, 355 35 2, 998 24.1 71.0 1, 440 4M 45 4,175 27.9 55.0 1,730 4M tinued and, of course, is at a high temperature, TABLE 3 to wit, about to C. If the carboxy v reactant is an anhydride needless to say no water Ex. N Amt. 1150211152- Time or Water or reaction appears; if the carboxy reactant is gg S01v8 g e- 533 52 8 g an acid water of reaction should appear and 60 I should be eliminated at the above reaction tem- #74 253 157 2% 8. 5 perature. If it is not eliminated I simply sepa- 57-3 55 177 3 rate out another 10 or 20 cc. of benzene by means g1; of the phase-separating trap and thus raise the 2 3 15 3 g temperature to 180 or .C., or even to 200 (3., 1 5 g if need be. My preference is not to go above #7-3 2 5 155 4% None 200 c it $33 13% 4% Y 5 None The use of such olvent is extremely satis- 5 lion) factory provided one does not. attempt to re- 5 *QTggg .move the solvent subsequently except by. vacuum 1% 3 distillation and provided there is no objection #Z'? 297 163 4Q 5133: .to a littl e idue. Actually, when these ma- $9? 1 r H Ii terials re used for a purpose such as demulslfica- 717-3 285 178 g g 'tion the solvent might just as well be allowed to #7-5 302 72 5 4 None remain. If the solvent is to be removed by dis- 1:5 "The procedure for manufacturing the -=es'ters has 'been'illustra'ted rby precedi-ng examples. iIf forzzmyreason reaction does :not takeplace :in :a manner that is acceptable, attention should 'be' directed :to the following details: .(a) Recheck the hydroxyl or .acetyl value of the oxypropylated :glycerol and use .a .stoichiometrically equivalent amount of acid; (b) if the reaction doesnotgpro- .ceed'with reasonable speed either raise the tem-r .peratures indicated .or .else extend the period .01:

time up tol2 .or Ll'fihoursnee'dbe; .(c') if necessary, use of par'atoluene sul'fon'ic acid or some other acid as a catalyst; (11') if the esterification does 'notjproduce a clear product a check should'bem'ad'e to see if an inorganic salt such as sodium "chloride "or sodium "sulfate is "not precipitating out. Such salt "shou'ld be eliminated, :at leastforexploration experimentation, and can be removed byiiltering. "Everything else being =equaiasthes'ize-of the molecu'le increases and the reactive hydroxyl radical represents -a smaller traction of the entire molecule and thus more cdiffieulty .is involvedrin 'obtaining c'ompletefesterification.

Even under the most carefully controlledqcon- &

ditions of oxypropylation involving comparatively low temperatures .and long time of reaction there are formed certain compoundswhose composition is *stiIl'obscure. "Such 'side'reaction products "can contribute a substantial ---propor'tion of the final cogeneric' reaction mixture. Various suggestions have been made as to the nature of these compounds, such as being cyclic polymers of .pro-

.pylene oxide, dehydration products "with theap pearance of a vinyl radical, .or isomers :01 pro- I pylen'e oxide or derivatives' there'offl. e.,iof an aldehyde, ketone, or allyl alcohol. In some'ininstances an attempt to react the stoichiometric amount of a polycarboxy acid with the oxyprogpylated derivative results in an excess of'the car-,- kboxylated reactant for the reason that apparently" under iconditions oi reaction less reactive hyrdroxyl :radicals are present 'than'indicated by the *hydroxylvalue. Under such circumstances there 'is simply a :residue of the carboxylic reactant which can be removed by filtration or,'if desired-,j the esterification procedure can be repeated using" an appropriately reduced ratio .of carboxylic zreactant.

'iEven'thedetermination of the .hydroxyl value" iby conventional procedure leaves much'to be der s'ired due either to the cogenericimaterials previously referred to, or for that matter, the ,pres- "In the above instancesI have permitted ,the

"solvents'to remain present "in the final reaction mass. "In other instances I have followed the ."same procedure using decalin or a'mixture o'fde- :calin or benzene in the same manner and ultimately'removed all the solvents'by vacuum distillation. Appearances of the final products are :much the sameas the diols before esterification :aand insome instances were somewhat darker in color and had a reddish cast and perhaps some- *whatmorevisc'ou's.

Previous reference has :been made to the fact that di'ols such as tjpolyprop l n sly l f pproximately 2,000 molecular weight, for example, have "been ester'ified with dicarboxy acids and employed as demulsitying agents. Onj'first examination the difierence between the herein described products and such comparable ,products appears "to "be rather insignificant. In fact, the difference is such that it "fails to explain the fact that compounds of the kindherein described maybe, and frequently are, 10%., 15% or 20% better on .a quantitative basis than the simpler compound previously described, and .demulsi'fy faster and give cleaner .oil in many instances. The method of making such comparative .tes'ts has been described in abooklet entitled Treating Oil Field Emulsion, used in the Vocational Training Courses, Petroleum Industry :Series, of the AmericanPletroleum Institute.

The difference, of course, does not reside in the carboxy acid but in the diol. Momentari-ly an effort will I'beim'ade to emphasize certain things in regard .to .the structure of a polypropylene glycol, such as polypropylene glycol of a 2000 molecular weight. Propylene glycol has a "primary alcohol "radical and a secondary alcohol radical. In this :sense the building unit which forms polypropylene ,glycols is not symmetrical. Obviously, "then, polypropylene glycol's can be obtained, at least theoretically, in which two secondary alcohol groups are united or a secondaryralcohol group is united to a primary alcohol group, etherization being involved, of course, in eachinstanoe.

Usually no efiort is made to differentiate between-oxypropylation taking place, for example, at .theprimary alcohol unit radical or the secondaryalcoho'l radical. Actually, when such products 'are .obtained, such as a high molal polypropylene glycol or the products obtained in the manner herein described *one does not obtain a single derivative such as HO(RO)nH in which n has one and only one value, for instance, I4, I 5 or l6, :or the like. Rather, one obtains a cogeneric mixfture of closely related or touching homologues. .These materials invariably have high molecular weights and cannot be separated from one an- :Iotherby any known procedure without decomposition. The properties of such mixture repre- ::sent ;the contribution of the various'individual members of thesmixture, On a statistical basis, of course, ncan'be appropriately specified. For practical purposes one need only consider the oxypropylationof a monohydricalcohol because in essence this is substantially the mechanism involved. ."Evenin such instances where one is concerned withuamonohydr'ic. reactant one caniru tditaw a single Iformulaan'd say that by following such procedure one ,can readily obtain or 901% or .ofsuch compound. .l'However, in :the case of at least monohydric initial reactants one can readilydraw the .formulasof 'a'large number of compounds which appear in some of the .;probable mixtures .or can "be prep'ar'ed as components and mixtures which are manufactured conventionally. I Simplyby'wa'y of illustration reference isfmade to the 'copending application of De ,Groote, Wil'tl and 'Pettingill, Serial No. 109,791, .filed 'iigglust n, 1949 '-(now Raterit"2,5"49;434, Apm 17, However, *mom'entar'ily greierrin "a ain monohydric initial *reactant' -lt is o l avio us "th t i? one selects-any "such simple hydroxylated 'compound and subjects such compound to oxyalkylation, such as oxyethylation, or oxypropylation, it becomes obvious that one is really producing a polymer of the alkylene oxides except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 20, 30, 40, or 50 units. If such compound is subjected to oxyethylation so as to introduce 30 units of ethylene oxide, it is well known that one does not obtain a single constituent which, for the sake of convenience, may be indicated as RO(C2H4O)30OH. Instead, one obtains a cogeneric mixture of closely related homologues, in which the formula may be shown as the following, RO(C2H4O)1H, wherein n, as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25, and perhaps less, to a point where 11. may represent 35 or more. Such mixture is, as stated, a cogeneric closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental Principles of Condensation Polymerization, by Flory, which appeared in Chemical Reviews, Volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact proportion of the various members of touching homologous series which appear in cogeneric condensation products of the kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration and how to repeat such production time after time without difiiculty, it is necessary to resort to some other method of description, or else consider the value of n, in formulas such as those which have appeared previously and which appear in the claims, as representing both individual constituents in which n has a single definite value, and also with the understanding that n represents the average statistical value based on the assumption of completeness of reaction.

This may be illustrated as follows: Assume that in any particular example the molal ratio of the propylene oxide to the diol is 15 to 1. Actually, one obtains products in which n probably varies from 10 to 20, perhaps even further. The average value, however, is 15, assuming, as pre viously stated, that the reaction is complete. The product described by the formula is best described also in terms of method of manufacture.

However, in the instant situation it becomes obvious that if an ordinary high molal propyleneglycol is compared to strings of white beads of various lengths, the diols herein employed as intermediates are characterized by the presence of a black bead, i. e., a radical which corresponds to the glycerol ether of propyleneglycol ethyl ether as previously described, 1. e., the radical o czHsoomo ci i Furthermore, it becomes obvious now that one has a nonsymmetrical radical in the majority of cases for reason that in the cogeneric mixture going back to the original formula n and n are usually not equal. For instance, if one introduces 15 moles of propylene oxide, 12. and n could not be equal, insofar that the nearest approach to equality is Where the value of n is '7 and n is 8. However, even in the case of an even number such as 20, 30, 40 or 50, it is also obvious that n and n will not be equal in light of what has been said previously. Both sides of the molecule are not going to grow with equal rapidity, i. e., to the same size. Thus the diol herein employed is differentiated from polypropylene diol 2000, for example, in that (a) it carries a hereto unit, i. e., a unit other than a propylene glycol or propylene oxide unit, (b) such unit is off center, and (c) the efiect of that unit, of course, must have some effect in the range with which the linear molecules can be drawn together by hydrogen binding or van der Waals forces, or whatever else may be involved.

What has been said previously can be emphasized in the following manner. It has been pointed out previously that in the last formula immediately preceding, n or n could be zero. Under the conditions of manufacture as described in Part 2 it is extremely unlikely that n is ever zero. However, such compounds can be prepared readily with comparatively little difi'iculty by resorting to a blocking effect or reaction. For instance, if the diol is esterified with a low molal acid such as acetic acid mole for mole and 7 such product subjected to oxyalkylation using a catalyst, such as sodium methylate and guarding against the presence of any water, it becomes evident that all the propylene oxide introduced, for instance 15 to 80 moles, necessarily must enter at one side only. If such product is then saponified so as to decompose the acetic acid ester and then acidified so as to liberate the water-soluble acetic acid and the water-insoluble diol a separation can be made and such diol then subjected to esterification as described in Part 2, preceding. Such esters, of course, actually represent products where either n or n is zero. Also intermediate procedures can be employed, i. e., following the same esterification step after partial oxypropylation. For instance, one might oxypropylate with one-half the ultimate amount of propylene oxide to be used and then stop the reaction. One could then convert this partial oxypropylated intermediate into an ester by reaction of one mole of acetic acid with one mole of a diol. This ester could then be oxypropylated with all the remaining propylene oxide. The final product so obtained could be saponified and acidified so as to eliminate the water-soluble acetic acid and free the obviously unsymmetrical diol which, incidentally, should also be kerosene-soluble.

From a practical standpoint I have found no advantage in going to this extra step but it does emphasize the difierence in structure between the herein described diols employed as intermediates and high molal polypropylene glycol, such as polypropylene glycol 2000.

The most significant fact in this connection is the following. The claims hereto attached are directed to a very specific compound, i. e., one derived by the oxypropylation of the glycerol ether of propylene glycol ethyl ether. In addition to this glycol ether, there are commercially available about a dozen more propylene glycol ethers. I have taken each and every one of these glycol 19 ethers and, as amatter of facta large number of ure-rs, subjected them to reaction with 'glycide and then oXypropylated the compounds and e terifid them in the manner described in the "instantapplication. I have then testedall these fproducts for demulsifica'tionand, at least to date, have not found another analogous compound thatwas equally efiective for demulsification and {also for certain other applications where surfaceactivity is involved. At the moment based on this knowledge this particular product appears unique -for reasons which are not understood. For purposse: clarifying this point I will'simply make reference to these various glycolethers which are available:

:PIQPilQIitQQYQ l me hy e r DiP C9PX EP QQ1 met l e r Tripropylene glycol methyl ether I .Mixture of mono-, di-, tripropylene glycol mthyl ,Q thsrs w Pm rlen glycol, ethyl he D pro yl ne y l et er r pr py ne. ol et y the Prop e e glycol. qp q l ther. -D r p len yco rm l ther. .Tripmpyl ne Q P QPy ether P opyl ne y o Ni tyl. e h r pro len col Ne u y eth Tripropylene glycol N-butyl ether PART Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or "after dilution with any suitable solvent, suchas water, petroleum hydrocarbons, such as benzene, toluene, Xylene, tar 'acid oil, "cresol, "anthracene oil, etc. Alcohols, particularly aliphatic 'alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl 'alcohoLhexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents such as pine oil, carbon tetrachloride, sulfur dioxi'de extract obtained in the'refining of petroleum, etc., may beemployedas diluents. Simi1a'rly,'the material or materials employed'as the demulsifyin: 'agentof' my process may be admixed with one .nr'mor'e of the solvents customarily used in connection with conventional 'demulsifying agents. 5 Moreovensaid'material ormaterials may be used alone "or "in admixture with other suitable well- *known classes of demul'sifyingagents.

"It is well'known'th'at conventional demulsifying agents may be usd in a water-soluble form, or in an oil-soluble form, or in a'form'exhibiting both oiland water-solubility. Sometimes they may be used in a form which exhibits relatively limited ,oil solubility. However, since such reagents are irequently used in a ratio oil to 10,000 or 1 to 20,000, or 1 to 30,000, oreven 1 to 40,000,or 1 to 50,000'as indesalting practice, such an apparent .insolubility in oil and water is not significant because said reagents undoubtedly have solubility .within such concentrations. This same fact is .true in regard to the material or materials employed as the demulsifying "agent of my process.

In'practicing my process'for resolving petro- .leum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the kind above .described is brought into contact with or caused ,to act upon the emulsion to'be treated, in any of the various apparatus. now generally used to resolve or break petroleum emulsions with a ich'einical reagent,- the'above procedure being used alone or in combination with other demulsifying treasure, such as the electrical "dead-arise c -M One type of procedure is'to accumulate "avoiume of emulsified oil in a tank and conduct a batch treatment type of demulsification procedure to recover clean oil. In this procedure the emulsion is admixed with the demuls ifier, for example by agitating the tank of emulsion and slowly dripping demulsifier into the emulsion. In some cases mixing is achieved by heating the emulsion while dripping in the demulsifier, de-

pending upon the convection currents in the emulsion to produce satisfactory admixture In a third modification ofthis type of treatment, a circulating pump withdraws emulsion from, e. g the bottom of the tank, and reintroduces it into the top of the tank, the demulsifier being added, for example, at the suction side of said circulating pump In a second type of treating procedure, the demulsifier is introduced into the well fluids at the well-head or at some point between the wellhead and the final oil storage tank, by means of an adjustable proportioning mechanism or proportioning pump. Ordinarily the flow of fluids through the subsequent lines and fitting suffices cent settling of the chemicalized emulsion.

Heating devices may likewise be incorporated in any of the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsion isto introduce the demulsifier either periodically or continuously in diluted or undiluted form into the well and to allow it to come to the surface with the well fluids, and then to fiow the 'chemicalized emulsion through any desirable surface equipment, such as employed in the other treating procedures. This particular type of application is decidedly usefulwhen the demulsifier is used in connection with acidification of calcareous oilbearing stratayespecially if suspendedin or'dissolved in the acid employed for acidification.

In all cases, it 'will'be apparent from"-the-fore- "going description, the "broad "process "consists simply in introducing a relativelysmallpropor- .tion of demulsifier into a relatively largeproportion of emulsion, admixing the "chemicaland emulsion either through natural flow or through special apparatus, with or without the application of heat, and allowing the mixture to stand quiescent until the undesirable water content of the emulsion separatesand settles fromthe-mass.

The following isa'typical installation.

A reservoir to hold the 'demulsifier ofthe kind described (diluted 'or undiluted) "ispla'ced at the well-head where the effluent liquidsleavethe well. This reservoir or container, which mayvary from '5'gallons to 50 gallons for convenien'ca'is connected to a proportioning pump which injects the demulsifier drop-wise into the fluids leaving the well. Such chemicalized fluids pass through the flowline into a settling tank. The settling tank consists of a tank of any convenient size, for instance, one which will hold amounts "of fluid producedin 4 to "24 hours (500 barrels to 2000 barrels capacity) and "in. which there 'is'a per pendicular conduit .fromthe top of the :tank to almost the very bottom so as to permit the incoming fluids to pass from the top of the settling tank to the bottom, so that such incoming fluids do not disturb stratification which takes place during the course of demulsification. The settling tank has two outlets, one being below the water level to drain oil the water resulting from demulsification or accompanying the emulsion as free water, the other being an oil outlet at the top to permit the passage of dehydrated oil to a second tank, being a storage tank, which holds pipeline or dehydrated oil. If desired, the conduit or pipe which serves to carry the fluids from the well to the settling tank may include a section of pipe with bafiies to serve as a mixer, to insure thorough distribution of the demulsifier throughout the fluids, or a heater for raising the temperature of the fluids to some convenient temperature, for instance, 120 to 160 F., or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as to feed a comparatively large ratio of demulsifier, for instance, 1 5,000. As soon as a complete break or satisfactory demulsification is obtained, the pump is regulated until experience shows that the amount of demulsifier being added is just sufficient to produce clean or dehydrated oil. The amount being fed at such stage is usually 1 10,000, 1 15,000, 1 20,000, or the like.

In many instances the oxyalkylated products herein specified as demulsifiers can be conveniently used without dilution. However, as previously noted, they may be diluted as desired with any suitable solvent. For instance, by mixing 75 parts by weight of the product of Example 30 with 15 parts by weight of xylene and 10 parts by weight of isopropyl alcohol, an excellent demulsifier is obtained. Selection of the solvent will vary, depending upon the solubility characteristics of the oxyalkylated product, and of course will be dictated in part by economic considerations, i. e., cost.

As noted above, the products herein described may be used not only in diluted form, but also may be used admixed with some other chemical demulsifier. A mixture which illustrates such combination is the following:

Oxyalkylated derivative, for example, the prodnot of Example 30, 20

A cyclohexylamine salt of a polypropylated naphthalene monosulfonic acid, 24%

An ammonium salt of a polypropylated naphthalene mono-sulfonic acid, 24%;

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%;

A high-boiling aromatic petroleum solvent, 1

Isopropyl alcohol, 5%.

The above proportions are all weight percents.

PART 6 As pointed out previously the final product obtained is a fractional ester having free carboxyl radicals. Such product can be used as an intermediate for conversion into other derivatives which are efiective for various purposes, such as the breaking of petroleum emulsions of the kind herein described. For instance, such product can be neutralized with an amine so as to increase its water-solubility such as tri-ethanolamine, tripropanolamine, oxyethylated triethanolamine, etc. Similarly, such product can be neutralized with amine which tends to reduce the water-solubility such as cyclohexylamine, benzylamine, decylamine, tetradecyl-amine, octadecyl- 2'2 amine, etc. Furthermore, the residual oarboxyl radicals can be esterified with alcohohsuch as low molal alcohol-s, methyl, ethyl, propyl, butyl, etc., and also high molal alcohols,'such as octyl, decyl, cyclohexanol, benzyl alcohol, octadecyl alcohol, etc. Such products are also valuable for a variety of purposes due to their modified solu-' in which R is the radical of a glycerol ether of propylene glycol ethyl ether; n and n are numerals with the proviso that n and 12. equal a sum varying from 15 to 80, and n" is a whole number not over 2, and R is the radical of the polybasic acid coon in which n" has itsprevious significance, and with the further proviso that the parent dihydroxylated compound prior to esterificati-on be water-insoluble.

2. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula ll (HO 0 o),.-Rc o canono R'o oamoh c imoo 0H),."

in which R is the radical of a glycerol ether of propylene glycol ethyl ether; 1:. and n are numerals with the proviso that n and n equal a sum varying from 15 to 80, and n" is a whole number not over 2, and R is the radical of the polybasic acid COOH in which n" has its previous significance, and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble and kerosene-soluble.

3. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

0 noooywnt xo C:Hu),.0R'O(CaHn0),,'yJR(C0011),

in which R is the radical of a glycerol etherof propylene glycol ethyl ether; 11. and n are numerals with the proviso that n and n equal a sum varying from 15 to 80, and n is a whole num- "tier Hanover- 2; and R is themzii'eai of the polyv *b'aslc'iid "in whih '71" as its previous significance, "said bo'lycarboxy acid having-not over 8 carbon atoms; "and with'the further proviso that the parent dihydroxylated compound prior-to esterific'ation be water insoluble and-keros'ene-so1ub1e.

'4; A 'pr'oc'es for' breaking "petroleum emulsions of the water-in-oil type characterized by subject mg the emulsion "to theacti'on bf a dem i-lsi'fier including hydldpljiiile synthetic products; {said liygrcphi'lefs yhthetie prpqucts being bhara'btri'zed by the followi-ri'gformiilaz n (HOOC)HRO(OCKHH)1|ORIO(C3HGO)WOR(CO 011) in which R is the radical of a glycerol ether of propylene glycol ethyl ether; n and 17; arenumerals'fwith the 'proviso that 'n anwweqqai 1a 'S u'm'""varyihg from ;15 toao, and R is-the radioal ofthe 'dic'arbok'y acid GO-OH wherein the (11- wherein the *diwherein the dithe di- REFERENCES "El TED The following references are of rcofd irfthe file of this-patent:

UNITED- STATES YPATENTS Number Name Date 2552528 DeGr o'ote May 15,1951 2562;878 'Bla'ir "Aug. '1, 1951 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA: 